A carbon monoxide leak in a building three blocks from the World Trade Center sickened 32 people and raised alarm that shuttered several busy blocks in lower Manhattan at the start of the workday today, authorities said.

The problem ultimately was traced to a broken boiler pipe in a grocery store basement, Fire Department Chief of Department James Leonard said.

But people started feeling faint around 8:30 a.M. Just as a worker opened a package in the basement, stirring worries that the parcel might have been poisonous.